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[Q] dead mmc -- ideas?

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By lexelby, Member on 28th July 2014, 04:27 AM
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I've been having a grand old time tinkering with my new TF701t. I unlocked the bootloader, tried a few ROMs, went back to stock, and I've been busily playing with it. Earlier this evening, it spontaneously shut down. I booted it back up and it shut down again after 5 minutes. I went into recovery and flashed the xposed disabler zip just in case xposed was to blame, but it shut down from recovery. Now it won't boot at all.

I can connect via ADB in recovery, and when I run dmesg, I see all sorts of nasty mmc0-related timeouts and errors. I can't even mount /system anymore. It's pretty clearly either an issue with the internal memory card or with the bus.

Does anyone have any idea how I can fix this or get it fixed? Of course, with an unlocked bootloader, I'm sure ASUS is going to give me all manner of grief and probably refuse to repair/replace what is clearly a hardware failure. Does anyone know if there's any way at all of replacing this kind of mmc card, or is it just part of the SoC? How screwed am I?


EDIT: Not screwed at all! See my post on page 2 for a fairly simple procedure to boot and run the tf701t (and quite probably many other devices) completely off of the SD card.
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29th July 2014, 02:14 AM |#2  
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Quote:
Originally Posted by lexelby

I've been having a grand old time tinkering with my new TF701t. I unlocked the bootloader, tried a few ROMs, went back to stock, and I've been busily playing with it. Earlier this evening, it spontaneously shut down. I booted it back up and it shut down again after 5 minutes. I went into recovery and flashed the xposed disabler zip just in case xposed was to blame, but it shut down from recovery. Now it won't boot at all.

I can connect via ADB in recovery, and when I run dmesg, I see all sorts of nasty mmc0-related timeouts and errors. I can't even mount /system anymore. It's pretty clearly either an issue with the internal memory card or with the bus.

Does anyone have any idea how I can fix this or get it fixed? Of course, with an unlocked bootloader, I'm sure ASUS is going to give me all manner of grief and probably refuse to repair/replace what is clearly a hardware failure. Does anyone know if there's any way at all of replacing this kind of mmc card, or is it just part of the SoC? How screwed am I?

See if you can mount /cache or /data. If you cannot then you have royally messed up your tablet. If you have replaced the recovery to something other than the original asus recovery then your best bet is to buy a logic board from ebay and replace it manually yourself.

I took mine to asus repair center and they said they will charge 200$ and 3 days to replace the logic board. I managed to buy the part for 70$ and do it myself. Just a side note, I bought and item that was AS-IS, so I am glad mine worked.
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29th July 2014, 02:19 AM |#3  
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Originally Posted by devbro

See if you can mount /cache or /data. If you cannot then you have royally messed up your tablet. If you have replaced the recovery to something other than the original asus recovery then your best bet is to buy a logic board from ebay and replace it manually yourself.

I took mine to asus repair center and they said they will charge 200$ and 3 days to replace the logic board. I managed to buy the part for 70$ and do it myself. Just a side note, I bought and item that was AS-IS, so I am glad mine worked.

Thanks for the tips!

It's quite weird. I booted it into recovery, and via adb I was able to mount /data fine and poke around. I unmounted, then mounted /system, and that worked fine too. Unmounted, rebooted, no dice; shutdown during reboot. Now I've booted back into recovery, and it locked up even trying to get into recovery, and I can't mount /data or /system (all result in long pauses and kernel errors).

You say I messed up my tablet... what do you think caused this? And yes, I've got CWM on here, although I could just fastboot the original recovery on if that would help...

Is there any way to boot this thing off of the external SD?

What was wrong with yours that required replacing the logic board?
29th July 2014, 02:58 AM |#4  
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Originally Posted by lexelby

Thanks for the tips!

It's quite weird. I booted it into recovery, and via adb I was able to mount /data fine and poke around. I unmounted, then mounted /system, and that worked fine too. Unmounted, rebooted, no dice; shutdown during reboot. Now I've booted back into recovery, and it locked up even trying to get into recovery, and I can't mount /data or /system (all result in long pauses and kernel errors).

You say I messed up my tablet... what do you think caused this? And yes, I've got CWM on here, although I could just fastboot the original recovery on if that would help...

Is there any way to boot this thing off of the external SD?

What was wrong with yours that required replacing the logic board?

It sounds like your boot is corrupted. There may be a way for ASUS to recover it without replacing the board.

My problem was that I messed up my boot and I could no longer flash anything or even modify files on the filesystems.
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29th July 2014, 03:02 AM |#5  
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Originally Posted by devbro

It sounds like your boot is corrupted. There may be a way for ASUS to recover it without replacing the board.

My problem was that I messed up my boot and I could no longer flash anything or even modify files on the filesystems.

Powering off completely seems to restore the device's ability to mount /system. I think touching a certain place on the emmc puts the controller in a bad state. I'm going to see if I can narrow down the bad blocks and partition around them or similar.

Barring that, where did you find a logic board for so cheap?
29th July 2014, 03:52 AM |#6  
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Originally Posted by lexelby

Powering off completely seems to restore the device's ability to mount /system. I think touching a certain place on the emmc puts the controller in a bad state. I'm going to see if I can narrow down the bad blocks and partition around them or similar.

Barring that, where did you find a logic board for so cheap?

If you can access it in adb, the first thing I would do is adb pull my data off the tablet.
Then you could run fsck on your partitions in an adb shell.
Maybe just a simple format of/system and /data would clear corruption already....

I don't know the correct fsck command for this tablet top of my head, but you have to unmount the partition you want to run it on and then something similar to this (this is for the /data partition of the TF700):
Code:
 e2fsck -fvyD /dev/block/mmcblk0p8
You seem to know your way around, I'm sure you can find it.
Good luck!
29th July 2014, 03:58 AM |#7  
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Originally Posted by berndblb

If you can access it in adb, the first thing I would is adb pull my data off the tablet.
Then you could run fsck on your partitions in an adb shell.
Maybe just a simple format of/system and /data would clear corruption already....

I don't know the correct fsck command for this tablet top of my head, but you have to unmount the partition you want to run it on and then

Code:
fsck /dev/target_partition_name
You seem to know your way around, I'm sure you can find it.
Good luck!

Nah, it's not simple fs corruption -- first thing I checked, but thanks for the suggestion Been poking at it for a few hours, and it seems like the actual mmc bus/chip is screwed, not just a bad block. I think replacing the logic board is the way to go. Anyone want to let a tf701t with a dead screen go for cheap?

And yeah, I know my way around a bit, but really only enough to sound like I know what I'm doing I recognized the problem because I lost my sgh-i777 to a very similar issue, a failing internal sd. Seems like the Achilles' heel of android devices.
29th July 2014, 04:08 AM |#8  
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Originally Posted by lexelby

Seems like the Achilles' heel of android devices.

I've owned close to a dozen Android devices. The SD still has to fail on me...
Maybe it's not the hardware, maybe it's - you
Anyway, good luck with this. Oh, and devbro found the logic board on ebay..
29th July 2014, 07:44 AM |#9  
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Quote:
Originally Posted by berndblb

If you can access it in adb, the first thing I would do is adb pull my data off the tablet.
Then you could run fsck on your partitions in an adb shell.
Maybe just a simple format of/system and /data would clear corruption already....

I don't know the correct fsck command for this tablet top of my head, but you have to unmount the partition you want to run it on and then something similar to this (this is for the /data partition of the TF700):

Code:
 e2fsck -fvyD /dev/block/mmcblk0p8
You seem to know your way around, I'm sure you can find it.
Good luck!

Quote:
Originally Posted by lexelby

Nah, it's not simple fs corruption -- first thing I checked, but thanks for the suggestion Been poking at it for a few hours, and it seems like the actual mmc bus/chip is screwed, not just a bad block. I think replacing the logic board is the way to go. Anyone want to let a tf701t with a dead screen go for cheap?

And yeah, I know my way around a bit, but really only enough to sound like I know what I'm doing I recognized the problem because I lost my sgh-i777 to a very similar issue, a failing internal sd. Seems like the Achilles' heel of android devices.

Quote:
Originally Posted by berndblb

I've owned close to a dozen Android devices. The SD still has to fail on me...
Maybe it's not the hardware, maybe it's - you
Anyway, good luck with this. Oh, and devbro found the logic board on ebay..

Be careful mmcblk0p8 is /data on the TF700, on the TF701 it is mmcblk0p14

Code:
name  device                    mountpoint  fs    description
/dev/block/platform/sdhci-tegra.3/ADF   /dev/block/mmcblk0p7      /ADF        ext4  ?
/dev/block/platform/sdhci-tegra.3/APD   /dev/block/mmcblk0p6      /APD        ext4  ASUS Product Demo
/dev/block/platform/sdhci-tegra.3/APP   /dev/block/mmcblk0p4      /system     ext4  Android OS
/dev/block/platform/sdhci-tegra.3/CAC   /dev/block/mmcblk0p5      /cache      ext4  recovery logs
/dev/block/platform/sdhci-tegra.3/CRA   /dev/block/mmcblk0p11                       ?
/dev/block/platform/sdhci-tegra.3/DTB   /dev/block/mmcblk0p2                        ?
/dev/block/platform/sdhci-tegra.3/EKS   /dev/block/mmcblk0p13                       NVEKSP
/dev/block/platform/sdhci-tegra.3/LNX   /dev/block/mmcblk0p3                        Linux kernel (8388608 b)
/dev/block/platform/sdhci-tegra.3/MDA   /dev/block/mmcblk0p12                       ?
/dev/block/platform/sdhci-tegra.3/MSC   /dev/block/mmcblk0p8                        empty (misc, bootloader etc.)
/dev/block/platform/sdhci-tegra.3/PER   /dev/block/mmcblk0p10     /persist    ext4  config/calibration data
/dev/block/platform/sdhci-tegra.3/SOS   /dev/block/mmcblk0p1                        Recovery kernel (8388608 b)
/dev/block/platform/sdhci-tegra.3/UDA   /dev/block/mmcblk0p14     /data       ext4  Android user data
/dev/block/platform/sdhci-tegra.3/USP   /dev/block/mmcblk0p9                        Staging (blob)
29th July 2014, 01:30 PM |#10  
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Originally Posted by sbdags

Be careful mmcblk0p8 is /data on the TF700, on the TF701 it is mmcblk0p14

Code:
name  device                    mountpoint  fs    description
/dev/block/platform/sdhci-tegra.3/ADF   /dev/block/mmcblk0p7      /ADF        ext4  ?
/dev/block/platform/sdhci-tegra.3/APD   /dev/block/mmcblk0p6      /APD        ext4  ASUS Product Demo
/dev/block/platform/sdhci-tegra.3/APP   /dev/block/mmcblk0p4      /system     ext4  Android OS
/dev/block/platform/sdhci-tegra.3/CAC   /dev/block/mmcblk0p5      /cache      ext4  recovery logs
/dev/block/platform/sdhci-tegra.3/CRA   /dev/block/mmcblk0p11                       ?
/dev/block/platform/sdhci-tegra.3/DTB   /dev/block/mmcblk0p2                        ?
/dev/block/platform/sdhci-tegra.3/EKS   /dev/block/mmcblk0p13                       NVEKSP
/dev/block/platform/sdhci-tegra.3/LNX   /dev/block/mmcblk0p3                        Linux kernel (8388608 b)
/dev/block/platform/sdhci-tegra.3/MDA   /dev/block/mmcblk0p12                       ?
/dev/block/platform/sdhci-tegra.3/MSC   /dev/block/mmcblk0p8                        empty (misc, bootloader etc.)
/dev/block/platform/sdhci-tegra.3/PER   /dev/block/mmcblk0p10     /persist    ext4  config/calibration data
/dev/block/platform/sdhci-tegra.3/SOS   /dev/block/mmcblk0p1                        Recovery kernel (8388608 b)
/dev/block/platform/sdhci-tegra.3/UDA   /dev/block/mmcblk0p14     /data       ext4  Android user data
/dev/block/platform/sdhci-tegra.3/USP   /dev/block/mmcblk0p9                        Staging (blob)

Thanks sdbags, nice catch. Btw, having developed ROMs for this tablet, do you think it's possible at all to boot android off of the external sd? It'd be helpful to know if I shouldn't even bother trying to figure out how.
29th July 2014, 10:13 PM |#11  
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Quote:
Originally Posted by lexelby

Thanks sdbags, nice catch. Btw, having developed ROMs for this tablet, do you think it's possible at all to boot android off of the external sd? It'd be helpful to know if I shouldn't even bother trying to figure out how.

Yes I have it working But haven't released it maybe after CROMi-X 7 is finished I will release the flash files that allow you to run one ROM internally and one rom off the card as ROM2SD

It's just an awful lot of work to maintain that doing it for the 300, 201 and 700 transformer crowd has kind of put me off doing for the 701. Also the internal mmc is faster than most fast sdcards so we won't see the benefits that especially the 700 users get.
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